The present invention relates to a bag-in-carton with a flexible inner bag adhered to inside surfaces of a substantially rectangular parallelepiped carton, and a method and device for forming the bag-in-carton.
As a liquid packaging container bag-in-cartons have been conventionally used. The bag-in-carton usually has a rectangular parallelepiped having a flat bottom panel, a top panel, and four flat side panels between the bottom and the top panels. The inner bag is adhered to the inside surfaces of the four side panels. The bag-in-carton is generally used in packaging liquids of low viscosities, such as juice, liquor, etc. Practically when a content is discharged from the bag-in-carton, air corresponding to a discharged amount of the content enters the bag-in-carton.
When the bag-in-carton is used in packaging a liquid of high viscosity, such as ink, or others, it is necessary to draw the liquid through the pouring spout when the liquid is discharged from the bag-in-carton. But it is difficult to let air in the inner bag. Accordingly it is necessary to deform the inner bag to decrease its volume corresponding to a discharge of the content in the inner bag. The conventional bag-in-carton whose inner bag is adhered to the four inside surfaces of the carton cannot have the inner bag deformed when a content thereof is discharged, which makes it impossible to use the bag-in-carton as it is in packaging a liquid of high viscosity.
Furthermore, in using the bag-in-carton in packaging ink for printing machines, the pouring spout of the bag-in-carton is connected to the connector of a printing machine to discharge the content of the bag-in-carton.
To meet the purpose of feeding a constant amount of ink to a printing machine, it is necessary that an ink feed amount per a unit hour is stably constant.
The conventional bag-in-carton cannot have achievements to fulfill these functions, and the following achievements are required.
1) The inner bag is deformed as ink is drawn out.
2) An ink feed amount is stably constant.